Understanding Arrow Spine Value in Archery: What It Is and Why It Matters

When it comes to choosing the right arrow for your recurve or compound bow, one of the most crucial—and often misunderstood—factors is arrow spine, commonly referred to as spin value (though technically, the correct term is spine, not spin). Getting the spine value right can make or break your shot accuracy, arrow flight, and bow performance.

In this article, we’ll break down what spine value means, how it affects your shooting, and how to choose the correct one based on your setup.

What Is Arrow Spine?

Arrow spine (not "spin") refers to the arrow shaft's stiffness—how much it bends when force is applied. When you shoot an arrow, it flexes as it leaves the bow. The amount it bends determines how it travels through the air and how accurately it hits the target.

There are two types of spine to understand:

• Static Spine: How much the arrow bends under a fixed weight (usually 1.94 lbs) at a standard 28-inch span. This is the value printed on most arrow shafts.

• Dynamic Spine: How much the arrow flexes during actual shooting, depending on the bow's draw weight, arrow length, point weight, and other variables.

How Spine is Measured

Arrow manufacturers measure static spine by suspending the arrow shaft at two points 28 inches apart and hanging a 1.94-pound weight in the center. The deflection (in thousandths of an inch) is the spine value.

Lower spine value = stiffer arrow
Higher spine value = more flexible arrow

For example:

• A 500 spine arrow bends 0.500 inches under the test weight.

• A 400 spine arrow bends only 0.400 inches—so it's stiffer.

Why Spine Value Matters

The correct spine value ensures the arrow flexes just enough to clear the bow and fly straight. An improperly matched spine can lead to:

• Inaccurate shots

• Erratic arrow flight

• Damage to equipment

• Poor grouping on target

Too Weak (Flexible) Spine:

• Arrow veers off to the side

• Excessive wobbling

• Risk of breaking on release

Too Stiff Spine:

• Incomplete flexing

• Arrow drifts away from the intended target

• Harsh vibration after release

Factors That Affect Arrow Spine Selection

Several elements determine the correct spine value for your arrows:

Choosing the Right Spine: A Quick Guide

Here’s a general guideline for recurve bows:

Tips for Beginners

• Start with arrows recommended by your coach or arrow spine chart based on your setup.

• Don’t cut arrows until you've tested them—length impacts spine.

• Tune your setup: Adjust nocking point, plunger tension, and brace height to improve arrow flight.

• If you’re unsure, go slightly stiffer—you can always soften the dynamic spine by increasing point weight.

Final Thoughts

Spine value might seem technical at first, but it's a cornerstone of good archery performance. Whether you’re target shooting or hunting, using arrows with the correct spine ensures smoother flight, better accuracy, and safer shooting.

If you're shopping for arrows, don’t just go by color or length—spine matters. Ask an expert, use a spine chart, or experiment to find your perfect match.